B-Line B52A-240HDG Eaton series strut back-to-back welded channel, .81" channel height, 240" channel length, 1.62" channel width, Steel, 12 Gauge, B52 channel type, Hot-dipped galvanized

Hot-dipped galvanized is the finish on the B52A channel, which is the coating specified for exterior runs, parking structures, rooftops and damp mechanical spaces where plain pre-galvanized strut would rust at the cut ends. Field cuts and drilled holes still expose bare steel, so touch them up with a cold galvanizing compound.

The B52 is a 1-5/8 inch wide profile at 1.62 inches, which is the standard strut width, so channel nuts, spring nuts, post bases, clamps and pipe straps sized for 1-5/8 inch strut engage its slot. The .81 inch depth is the half-height (13/16 inch) profile, so deep-throat fittings made for the full 1-5/8 inch tall channel will not sit correctly.

Back-to-back means two channel sections welded spine to spine so the slotted openings face opposite directions. You get roughly double the section and the ability to hang or attach off both faces, which is why it is used for trapeze hangers, free standing rack uprights and longer unsupported spans than a single piece of strut will carry. For short runs bolted flat to structure, a single channel is the simpler pick.

Order it as B52A-240HDG from Eaton B-Line. That number breaks down as B52 channel profile, 240 inch length, HDG for hot-dipped galvanized. Nuts, bolts, brackets and end caps are separate line items, so build those into the takeoff.